Hearing, olfactory, and cognitive impairments are common health problems for aging adults. Age-related declines in sensory and cognitive function contribute to decreased quality of life in older adults. The purpose of this 21-yrfollow-study of a population-based cohort is to identify factors contributing to declines in sensory (hearing and olfaction) and cognitive function with aging. Specifically, the aims are to determine if biomarkers of neuroprotection are associated with the incidence of sensory (hearing and olfaction) and cognitive impairments; if these markers or markers of inflammation and atherosclerosis are associated with declines in auditory and cognitive function or olfaction thresholds; if shared risk factors (inflammatory, vascular and neural factors) contribute to the association between sensory disorders and risk of cognitive impairment; and to identify factors contributing to successful aging, measured by sensory and cognitive function. Subjects are participants in the population-based Epidemiology of Hearing Loss Study (EHLS) and were 48-92 years of age at the baseline examination (1993-95). The cohort was re-examined in 1998-2000, 2003-05, and 2009-2010. The proposed examination will use the same standardized protocols for hearing, olfaction, and cognitive testing, cardiovascular measures, and health questionnaires used in the last phase. New measures will include olfaction thresholds and questions about psychological traits. Laboratory analyses for a panel of biomarkers (cystatin-c, brain-derived neurotrophic factor, insulin-like growth factor-1, Cortisol, and aldosterone) will be conducted on stored samples from two time points. Analyses will use the repeated measures available from this longitudinal study to focus on the effects of long-term exposures. Results from this study will contribute to identifying new strategies to slow the declines in hearing, olfactory, and cognitive function with aging. Our multi-system approach will provide important information useful for planning interventions to promote successful sensory and cognitive aging.